金属包层阶跃平板介质波导导模的二级微扰分析

Second Order Perturbation Analysis of Guided Modes in Metal-Clad Planar Waveguides

直接求得的复本征值方程的解作为精确解，由微扰理论得到的一级和二级近似结果与之进行了分析比较，结果表明微扰法是相当好的近似方法，它们给出了与精确值符合相当好的数值结果。分析结果还表明微扰法的二级近似结果对一级近似结果的修正很小，一级近似已可以给出足够精确的结果。

The complex eigenvalue equation of a metal-clad planar waveguide is solved exactly. The results of thd first and the second order approximation obtained by the perturbation theory are compared with exact results. It is demonstrated that the perturbation method gives results in good agreement with those obtained by exact solution of complex eigenvalue equation. It is also demonstrated that the difference between results of the first and the second order approximation is quite small and usually the first order approximation gives sufficiently accurate results.